PRESIDENTIAL LECTURE - International Spinal Cord Society



PRESIDENTIAL LECTURE

Strategy for conservative management of vertebral fractures;

Current Management of Traumatic Spinal Injuries and concerns about the interpretation of outcomes of future interventions

W S El Masri(y)

Consultant Surgeon in Spinal Injuries

President : International Spinal Cord Society

INTRODUCTION

Traumatic spinal cord injuries (TSCI) are life changing events. Their effects are multiple and complex requiring the expertise of a well trained and well coordinated multidisciplinary team 1. TSCI are not however catastrophic injuries unless they are mismanaged.

With simultaneous Active Physiological Conservative Management (APCM) of the injured spine, the multisystem physiological impairment and malfunction and with adequate planning, monitoring and recalibration of the management especially during the transitional period between spinal shock (areflexia) and recovery of reflexes; the majority of patients with incomplete spinal cord injury patients recover significantly to ambulate 2,3

With simultaneous equally good attention to the psychological, social, emotional, financial, vocational, environmental and economic consequences, patients who do not recover ambulation and those who do can, lead healthy, fulfilling , productive and competitive lives 2

Non Orthopaedic Effects of Traumatic Spinal Injuries with Neural Tissue Damage :

These are wide ranging and varied

• Physiological Instability (PI) of the Spinal Cord

The injured spinal cord is physiologically unstable due to loss of auto-regulatory mechanisms, disruption of the blood brain barrier and a range of metabolic, cellular and cell membrane disturbances that occur following injury. This PI renders the spinal cord vulnerable and unable to defend itself from non- mechanical complications such as hypoxia, sepsis, hypotension, hypertension, anaemia 4. These can easily occur in the neurologically impaired patient in further manifest neurological deterioration or indeed lack of neurological recovery (silent deterioration). In the absence of blood loss, the administration of vaso-pressors to patients presenting in spinal shock with bradycardia is a source of concern to the authors, since due to loss of auto regulatory mechanisms of the spinal cord, an increase of blood pressure may result in bleeding within the cord and further detriment. What perhaps may not be appreciated is that the hypotension of spinal shock is a “low resistance” hypotension due to sympathetic areflexia causing generalised vasodilatation as opposed to the high resistance hypotension associated with blood loss.

While early mobilisation/verticalisation of the neurologically intact patient with a stable or surgically stabilised fracture is advantageous since the patient can be discharged home soon after, early mobilisation/verticalisation of a neurologically impaired patient with a physiologically unstable spinal cord, is unlikely to offer the same advantages and can be hazardous 3 (see below)

• Generalised multi-system physiological impairment (MSPI) and malfunction (MSMf) . The functioning of the various systems of the body is abnormal and now depends on the reflex activity of the spinal cord (SC) distal to the level of injury as well as on the intrinsic ability of the various systems of the body to function unconnected to the brain. 2,3

• The reflex activity of the SC segments below the level of injury changes often unpredictably throughout the patient’s life affecting function. Rapid changes are particularly more pronounced during the transition period between spinal shock and full recovery of spinal cord reflexes which can last for a few months. Consequently predictable and unpredictable changes in the functioning of the various systems of the body occur 2,3.

• Intersystem effects

The interruption of the higher co-ordinating and moderating functions of the brain usually result in a wide range of multiple cascading intersystem

effects and in complications that are rarely seen in other conditions 2,3.

• Potential of wide range of disabilities and wide range of complications :

Because of the impaired physiology, impaired function and the interruption of the higher co-ordinating and moderating functions of the brain, individual system malfunction becomes a source of one or more disability and a potential source for a wide range of complications of various severity ref 1. Complications following SCI increase morbidity cost of treatment and the already heavy burden to patients and family members. Some can potentially cause death others e.g pressure sores can result in high risk of permanent recurrence for life.

• The sensory impairment/loss present diagnostic challenges to clinicians since the usual anticipated symptoms and physical signs of associated injuries, pathology and/or complications are unreliable in these patients.

• The added non medical effects such as loss of independence, social, emotional, financial, vocational, environmental and economic consequences add to the burden of the patient and all those involved with his/her management.

With good comprehensive management and support by an expert multidisciplinary team, the impact on medical, physical and mental health can be markedly diminished and almost all complications can be mitigated or significantly minimised.

CHANGE IN THE STANDARD OF CARE OF THE INJURED SPINE

In the last 3-4 decades many factors have combined to change the standard of care in patients with traumatic spinal cord injuries and promote surgical decompression and stabilisation.

Advances in imaging with the advent of CT & MRI scans, improvement of design and material of spinal instrumentation, improvement in anaesthetics, patients beliefs and expectations, pressures and fragmentation of funding sources, changes in Clinicians’ training and allied professionals’ were all factors favouring surgery .

One of the most important factors was however, a genuine belief Based on Laboratory Animal Findings that Traumatic Spinal Canal Encroachment and Cord or Cauda Equina Compression can prevent neurological recovery and/or cause further damage to neural tissue. This seems to have popularised and legitimised the global practice of Surgical Decompression and Stabilisastion of the Injured Spine as first choice of treatment.

There is a wide range of interventions other thank surgery that claim benefit to the neurology of the SCI individual that have been developing over the last couple of decades. Most of the outcomes have been and are being compared to surgical outcomes

THE RJAH OSWESTRY DILEMMA

With the introduction of CT in 1987 followed by MRI in 1994 Oswestry had to define its Strategy as regard the management of TSCI.

The results of Conservative Management in this Orthopaedic Institution with dedicated spinal surgeons were excellent. We had confirmed the findings of Frankel et al in 1969 5 and the European and Australian groups who had subsequently established reproducibility 6. We had also observed that with Conservative management and equal attention to the Physiological Instability of the injured spinal cord and the Biomechanical Instability of the spinal column; the majority of patients with incomplete cord injuries made significant neurological recovery irrespective of the degree of canal stenosis, malalignment, anticipated canal encroachment and cord compression as seen on X rays.

Furthermore the incidence of pain following Conservative Management was less than 10% in both the short and the very long term

A decision had to be made.

THE PROCESS

We trusted our judgement and observations that the great majority of patients who had the clinical prognostic indicators of recovery recovered 7, 8, 9, 10, 11. We assumed that some if not many of these patients must have had spinal canal encroachment and neural tissue compression that could not be seen on plain X Rays.

We also reviewed the literature related to the controversy around the hypothesis of the secondary injury 3,6 . We also studied the literature about the Laboratory findings on experimental animals. We could not accept that the level of evidence was strong enough to be applicable to humans especially that there were relevant differences between the species.

LABORATORY FINDINGS

We considered it unlikely that the 20 to 60 million years of evolution between the laboratory (rodents, cats, dogs) and humans would have selectively spared the spinal cord from evolving . There were other factors as well:

We reflected on the effects of surgery on blood pressure, spinal cord blood flow and on the respiratory functions and stipulated they are likely to be different between quadrupeds and in humans.

We considered the difference in the duration of spinal shock measured in hours in the laboratory animal and in days to weeks in the majority of humans. We thought this is likely to add to the differences in the effects of mobilisation on neurological functions between quadrupeds and bipeds.

We considered the difficulty in assessing subtle gait abnormalities in the laboratory animal and relative ease of detecting minor gait abnormalities in humans and believed this may explain why some of the observed positive results of interventions in the laboratory animal could not be confirmed in humans.

We therefore decided, with some trepidation, to determine the significance of traumatic canal encroachment and cord compression in humans while continuing treating our patients conservatively rather than implement change of practice and carry out routine surgical decompression and stabilisation.

Conservative treatment consisted of 4-6 weeks of bed rest during which attention is equally given to the multisystem impairment and malfunction as well as to the non medical effects of the spinal cord injury. This followed by mobilisation in a brace for a further 6 weeks during active locomotor rehabilitation and in parallel with the continuing treatment and support.

NEUROLOGICAL OUTCOME

TRAUMATIC SPINAL CANAL ENCROACHMENT

The first case reports to suggest that traumatic canal encroachment as demonstrated by computerised tomography does not correlate with the degree of neurological impairment, does not prevent neurological recovery and does not result in neurological deterioration of cord function were published by El Masri et al in 1992.6,12 The same conclusions were made by reviewing the outcome of conservative treatment of 50 consecutive patients with between 10% to 90% canal encroachment in Frankel C, D and E groups. Patients in Frankel C&D group recovered ambulation. None of the patients in Frankel C, D and E groups deteriorated neurologically or otherwise . This work was presented to the second Neurotrauma Symposium in Holland 1993 and the American Federation of Spinal Surgeons in February 1994. It was also published in abstract form El Masry et al 1993 13,14 Other groups have since published similar findings.15,16,17 There is no evidence to suggest that early or late surgical decompression achieves better or earlier neurological recovery than APCM in humans with incomplete cord or cauda equina injury.

Equally there is no evidence to suggest that surgical decompression is beneficial to humans with complete traumatic cord or cauda equina injury . In 53 consecutive patients with complete cord injury (FA) but with pin prick sensation in the zone of partial preservation will recover significant and useful motor power in the correspondent myotomes 11 . A neurological level higher than the bony level of fracture is another good prognostic indicator of zonal recovery 11

TRAUMATIC SPINAL CORD COMPRESSION

Unlike in the laboratory situation where it is observed that the longer the cord compression is unrelieved the more damage and neurological loss occurs; Traumatic Cord Compression does not appear to prevent neurological recovery in humans, with incomplete cord injuries 2,14,18,3,19 figure. Equally interesting is that traumatic cord compression is not necessarily always associated with neurological damage and maintenance of neurological free status can be maintained without surgical decompression or realignement. Fig Y

Since the installation of the MRI scanner in our institution we have been monitoring (both prospectively and retrospectively) the neurological progress of conservatively managed patients with cord compression. The preliminary results indicate that the same clinical prognostic indicators of recovery apply whether there is cord compression or not. What is perhaps not highlighted enough is that Surgical decompression does not seem to be beneficial to either the laboratory animal or to humans when the severity of the initial impact on the spinal cord is beyond a certain magnitude as recovery will not occur 20,21,22

TRAUMATIC BIOMECHANICAL INSTABILITY (BI) OF THE SPINAL COLUMN

The most biomechanically unstable fractures heal within 6-12 weeks from injury when Biomechanical Stability (BS) is restored. Ligamentous injuries, however, can take much longer to heal. BI is therefore time related. Containment of the most Biomechanically Unstable injuries can be easily and safely maintained with APCM in recumbency for 4-6 weeks followed by bracing during mobilisation for a further 6 weeks. The great majority of injuries become biomechanically stable, pain free, allowing an excellent range of movement. Mechanical damage or further damage to the spinal cord at the site of the fracture is extremely rare in recumbency.

There is no evidence to suggest that surgical stabilisation enhances the speed of healing or achieves stability earlier than with APCM except in pure ligamentous injuries with translation and without bony damage when about 50% of the patients develop prolonged BI and are likely to require surgical stabilisation..

The spinal canal has been known to remodel since the mid eighties. Often the vertebral body remodels as well with APCM.

Admittedly the incidence of kyphotic deformities is lower following surgical stabilisation than following APCM, however the greatest majority of these kyphotic deformities are painless. The discrepancy between kyphotic deformity and pain has been known for some time 6. A painless 40-50o kyphotic deformity enhances wheelchair bound patients’ independence and is certainly much preferable to a stiff straight neck or back.

Admittedly the incidence of kyphotic deformities is lower following surgical stabilisation than following APCM, however the greatest majority of these kyphotic deformities are painless. The discrepancy between deformity and pain has been known for some time 3. A painless kyphotic deformity enhances wheelchair bound patients’ independence and is certainly much preferable to a stiff straight neck or back.

The benefit of surgical decompression to neurological outcome and of surgical stabilisation were not the only beliefs that required challenging.

SURGERY FOR: EARLY MOBILIATION (EM) - REDUCTION OF COMPLICATIONS - REDUCTION OF PERIOD OF REHABILITATION & HOSPITALISATION - FACILITATION OF NURSING:

There was a general belief and an assertion that surgery was beneficial to achieve early mobilisation, reduce complications of recumbency , expedite rehabilitation and shorten hospitalisation time.

Although we were in agreement that Early Mobilisation is certainly advantageous to neurologically intact patients who can be discharged soon after successful surgical stabilisation, there were many reasons why this was not the case in the neurologically impaired patient.

Over six decades ago Guttmann demonstrated that the complications of recumbency in SCI patients are caused by the inadequate management of the recumbent patient and are almost completely preventable.

Furthermore the physiological responses to posture differ between the neurologically intact and the neurologically impaired.

Posture and the Respiratory System

Although the vital capacity the neurologically intact patient increases in the vertical position , Early mobilization before return of reflex activity of patients with complete upper thoracic and cervical cord injuries is associated with reduction of lung volumes and vital Capacity 23, 24, 25, 26, a potential drop of oxygen saturation as well as marked Postural Hypotension. These findings have been confirmed repeatedly.

The combination of hypotension, reduced vital capacity and potential reduction of oxygen saturation may not only further impair cord functions, but also imposes great limitations on the physical ability of the patient who requires energy, motivation and a sense of well being to engage in the arduous, tedious and demanding process of Rehabilitation.

Assisted coughing, which is essential to get rid of bronchial secretions in patients with paralysed abdominal muscles who are unable to expectorate, is easier and more effective in recumbency than in the vertical position. The struggle against gravity to achieve successful assisted expectoration is minimised in recumbency.

The incidence of chest infections in tetraplegic and paraplegic patients treated with APCM in the acute phase in the MCSI is less than 3% . The incidence of tetraplegic and paraplegic patients requiring short term ventilation is less than 2% when they present in the acute phase breathing spontaneously

and without associated chest injuries or past history of chronic respiratory disease.

Postural hypotension is most profound during the stage of spinal shock. EM of patients with cord injury but with biomechanically stable injuries can cause temporary neurological deterioration that recovers immediately when the patient is returned to recumbency.(phys. Ins). Administration of ephedrine before verticalisation abolishes both the drop of blood pressure and the neurological loss suggesting that cord haemodynamics influence neural functions and suggesting that the physiological instability of the spinal cord needs at least equal attention to the biomechanical instability of the spinal column.

Posture and Pressure sores

The risk of pressure sores over the ischial tuberosities and sacro coccygeal prominences is indeed increased when the patient is mobilised in the wheel chair particularly during the stage of spinal shock when the skin blood flow is at its poorest. The forces which in recumbency are spread across all bony prominences become concentrated on the ischial tuberosities and sacro coccygeal prominences when the patient is mobiliseed/verticalised.

Posture , Rehabilitation and Total Hospitalisation

There is no evidence to suggest that early mobilisation in patients with SCI shortens the period of treatment of the multi system impairment and malfunction, rehabilitation and or hospitalisation. Such periods are influenced if not governed by many factors: the range of services provided by the hospital to the various effects of the SCI, the model of service provision , the subjective experience of the clinician, the system of funding, the system of social support and the ewaponsibility of the hospital to the patient following discharge from hospital.

Moreover there is no homogenicity in the definition of the end point of the episode of treatment. Furthermore there is no evidence to suggest that the period of hospitalisation during the acute stage reflects the total hospitalisation for the management of the multisystem physiological impairment and malfunction, rehabilitation and return of the patient to his/her own community.

PROGNOSTIC INDICATORS OF RECOVERY

The neurological findings at 48 – 72 hours from injury are essential in predicting neurological recovery. Over 85% of tetraparetic patients who present in the first 72 hours from injury with any distal movement however isolated, little and/or patchy (FC), and over 75% of patients who present 48 – 72 hours from injury with no motor power but with preservation of pin prick sensation down to S3 (FB) will recover to walk again at 4-6 months from injury and the great majority in one year 7,8,9,10 provided they are not harmed by the treatment. In 53 consecutive patients with complete cord injury (FA) but with pin prick sensation in the zone of partial preservation will recover significant and useful motor power in the correspondent myotomes 11 . A neurological level higher than the bony level of fracture is another good prognostic indicator of zonal recovery 11

POSSIBLE MECHANISMS OF NEUROLOGICAL DETERIORATION ASSOCIATED WITH SURGICAL INTERVENTION:

Although surgery in skilled hands and in an ideal environment is generally safe, the true incidence of manifest neurological deterioration or lack of neurological recovery (silent deterioration) is unknown.

Mechanisms of neurological deterioration associated with surgery range from mechanical damage during handling preoperatively, per operatively or during intubation; clamping of a major feeder to stop bleeding; hypotensive or hypoxic attack during anaesthesia; post operative bleeding around the cord or cauda equina ; post operative sepsis and post operative premature failure of implant.

Close monitoring of neurology in Conservatively managed patients in our institution revealed a temporary increase in density or ascent by one or two levels at around 48-72 hours from injury in 10%-15% of patients. The great majority of of these patients recover to at least initial level or better. This we think is related to oedema of the spinal cord which subsides within 2-3 weeks from injury 8,11.

With modest care, permanent and significant neurological deterioration in recumbency is extremely rare irrespective of the degree and severity of the biomechanical instability. Most of the significant and permanent deterioration occurs when the patient with a biomechanically unstable spine and/or a physiologically unstable spinal cord is sat up in bed or mobilised out of bed.

We believe that patients undergoing any type of treatment should be given this information

RJAH OSWESTRY INDICATIONS FOR SURGEY:

The uncontrolled epileptic , the mentally challenged and patients who are unable to comply with bed rest are likely to be benefit from surgical stabilisation as they are likely to be difficult to manage Conservatively . Patients with Biomechanical Instability from pure ligamentous injuries without bony injury are at risk of developing late instability and may opt for early surgery.

Patients who exhibit signs of neurological deterioration with evidence of further compression of neural tissues on MRI may benefit from surgical decompression.

Discussions

Patients with incomplete cord injuries make significant neurological recovery irrespective of the degree of canal stenosis, canal encroachment, malalignment and or cord compression 3,6,9,14 provided both the BI of the spinal column and the PI of the spinal cord are well contained.

The findings in the laboratory animal do not appear to be mirrored in the clinical situation. This could be related to differences between species during evolution as well as the differences in the effect of the spinal cord pathophysiology between quadripeds and bipeds especially on the autonomic and respiratory system. In any case translation from the laboratory animal to the clinical situation requires caution 27.

We believe, based on current knowledge and level of evidence , there is no need for immediacy in surgical decompression and/or stabilisation and/or any other intervention. Surgery should not supersede the need of a thorough neurological examination, adequate enough to compare with, monitor and determine neurological outcome at later stages of injury. This should apply to any intervention not only surgery.

We also believe that should surgery be contemplated it should be carried out by the most experienced and skilled spinal surgeon in an environment where patients with such generalised physiological impairment can be looked after and supported safely.

In the absence of the best surgical skill and expertise and/or appropriate infrastructure all patients with SCI can be treated Conservatively safely in recumbency until they are referred to a spinal injury centre where they can also have expert simultaneous treatment to all the medical and non medical effects of the spinal cord injury.

CONCLUSIONS

Conservative management of the injured spine is safe and easy to conduct provided the patient is agreeable to remain in recumbency for up to 6 weeks.

The outcomes of Conservative management are excellent and remain unchallenged by any of the wide range of interventions

Conservative Management can be conducted in any Institution as long as the patient is agreeable to remain recumbent . The multisystem physiological impairment and malfunction and the non medical effects are much more demanding and require the skills of a well coordinated multi disciplinary team of well trained and experienced staff that can only be found in dedicated SI Centres. The majority of Spinal Injury Centres also have the expertise of skilled Surgeons and can offer equally skilled Conservative and Surgical management with the added benefit of informed consent by the patient.

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